JPH0443574B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a silver halide photographic material provided with a back coat layer, and more particularly to a silver halide photographic material provided with a back coat layer which has improved suitability for an automatic processor. More specifically, the present invention relates to a silver halide photographic material with improved tape adhesion, which will be described later. Usually, a silver halide photographic material is composed of a support and a silver halide photographic constituent layer provided on the support. Such silver halide photographic constituent layers include a silver halide photographic emulsion layer, a protective layer, a subbing layer, an intermediate layer or color mixing prevention layer, an antihalation layer or filter layer, an ultraviolet absorbing layer, etc., and combinations thereof. It is what was done. For example, a single silver halide photographic material is
A silver halide emulsion layer and its protective layer are provided on a support. In addition, a multilayer silver halide color photographic material has a multilayer arrangement in which a blue-sensitive emulsion layer and an intermediate layer, a green-sensitive emulsion layer and an ultraviolet absorbing layer, a red-sensitive emulsion layer and a protective layer, etc. are sequentially provided on a support. Each color-sensitive emulsion layer contains yellow, magenta, and cyan color forming couplers. Incidentally, supports for silver halide photographic materials have conventionally been made of films such as polyethylene terephthalate film, cellulose triacetate film, polystyrene film, polycarbonate film, paper as a substrate, and resins capable of forming films on both sides, often polyolefin resins. Hydrophobic supports such as resin-coated papers coated with In particular, polyolefin resin-coated paper is increasingly being used as a support for photographic prints in place of the conventionally used baryta paper. The reason for this is that the polyolefin resin-coated paper used as a photographic support is hydrophobic, so the development of photographic printing paper is faster than that of baryta paper.
This is because the processing liquid is less likely to penetrate into the base paper layer during the fixing process, which has the advantage of shortening processing times such as washing and drying. However, these photographic hydrophobic supports have several drawbacks. A well-known drawback is that silver halide photographic materials with these hydrophobic supports tend to become statically charged and attract dirt, dust, etc. during their handling.
In addition to causing various spots such as water repellency, desensitization, and fogging, the accumulated static electricity is discharged, resulting in photographic properties called static marks in the silver halide photographic emulsion layer. Moreover, it may cause extremely unpleasant partial fogging. For this reason, it is known that an antistatic coating layer called an antistatic back coat layer is provided on the back side of a silver halide photographic material having a hydrophobic support, that is, on the surface of the support that is not coated with the silver halide photographic constituent layers. It is being For example, in order to provide antistatic performance,
The use of colloidal silica described in Japanese Patent Publication No. 30298, colloidal alumina described in Japanese Patent Publication No. 52-18020, and compounds having various carboxyl groups described in Japanese Patent Publication No. 58-9408 is known. . In addition, ethylene maleic anhydride copolymer described in Japanese Patent Publication No. 57-12980,
56859, a water-soluble polymer compound obtained by copolymerizing an ethylenically unsaturated copolymerizable monomer having 4 or more carbon atoms with maleic anhydride, or a salt thereof, Japanese Patent Publication No. 57-53940 It is also known to use organic polymer antistatic agents such as the water-soluble film-forming polymeric anionic polymer electrolytes described in No. However, when using silver halide photographic materials consisting of a hydrophobic support provided with these back coat layers and silver halide photographic constituent layers,
It had one or more serious shortcomings. For example, when used in high-sensitivity silver halide photographic materials, it may not be possible to sufficiently prevent static marks, or the antistatic performance may deteriorate after processing, causing prints to stick to each other, making handling inconvenient. Some of the components may detach, resulting in undesirable sludge build-up, or the back coat layer may be fragile or have weak adhesion to the hydrophobic resin, causing the interior of the printer to be damaged during exposure of silver halide photographic materials. There were cases in which the coating equipment was contaminated with powder, and the coating equipment was contaminated at the stage of coating the silver halide photographic constituent layers. In addition, as is often done in recent years, halogenation is carried out in printers for the purpose of automatically cutting roll-shaped silver halide photographic materials by clearly marking the boundaries between the screens, or for the purpose of writing information about the screens. Type printing is sometimes carried out on the back coat layer on the back side of silver photographic materials, but problems have arisen in that the type ink is washed away in the processing bath or the color becomes diluted, making it impossible to fully demonstrate its function. In particular, in the case of multilayer silver halide color photographic paper, most of which is automatically printed and automatically cut in roll form, the ability to print on the back coat layer in the printer is an important characteristic.
There has been a strong demand for a multilayer silver halide color photographic paper in which the back coat layer is clearly printed even after development. By the way, type printing as used in this specification refers to printing in which ink or a substrate such as a type ribbon containing ink is interposed between the back coat layer surface of a silver halide photographic material and a type consisting of dots or inscriptions. This indicates that ink is printed in a type-like manner on the surface of the back coat layer by pressure bonding, preferably by an impact method. Furthermore, as already mentioned, silver halide photographic materials having a hydrophobic support are characterized by so-called rapid processing, in which the development processing time is shortened.
However, if a silver halide photographic material having a hydrophobic support with a back coat layer on which type printing has been applied is developed after 60 minutes or more, especially 3 hours or more, after type printing, Even though it is possible to obtain prints with clear type imprinting even after processing, it is possible to obtain prints with clearly typed imprints within 60 minutes after type imprinting, especially the shorter the elapsed time since type imprinting. This causes serious problems such as poor type imprintability and, in extreme cases, almost no type imprint remaining, which is completely contradictory to the rapid processability benefits of silver halide photographic materials having hydrophobic supports. I found out. In addition, another problem occurred in that the tape adhesiveness deteriorated, which will be described later. Generally, a roll of photographic paper that has been exposed to light in a printer is stored in a cartridge and transported to a roll of photographic paper processor, and the leading edge of the roll of photographic paper is processed (a roll of photographic paper that is about to be developed). When the photographic paper is the leading roll of photographic paper, it is bonded to the end of the leader film (leader film) using an adhesive tape, so-called leader joint adhesive tape, and is successively developed one after another. Examples of joining methods include, for example, using double-sided adhesive tape between stacked photographic papers;
A method of wrapping one-sided adhesive tape around stacked pieces of photographic paper, one-sided adhesive tape on the back of two pieces of photographic paper that are not overlapped, or one-sided adhesive tape made by pasting double-sided adhesive tape on the back of a piece of photographic paper. There are various methods of joining, but usually at least one of the two preceding and following photographic papers has an adhesive tape and an adhesive surface on the back side. While this joint passes through a roll photographic paper processor, tensile force is also applied to the adhesive surface between the back of the photographic paper and the adhesive tape. There was a problem that the adhesive surface with the adhesive tape would peel off partially or in extreme cases, completely during the processing solution or during the drying process, and in the worst case, subsequent development processing of photographic paper would become impossible. . As mentioned here, we will refer to the tendency of the adhesive tape to separate from the back side of the photographic paper during handling as simply having poor tape adhesion, and to refer to cases where there is no such problem as having good tape adhesion. Although the back coat itself is significant and necessary as described above, such deterioration in tape adhesion causes significant inconvenience to photographic paper processors and is unacceptable. Accordingly, a primary object of the present invention is to provide an improved silver halide photographic material having a hydrophobic support provided with a backcoat layer. That is, it is sufficiently antistatic and therefore prevents the formation of static marks, prevents prints from sticking to each other after processing, and does not cause contamination of the processing bath, printer, etc. To provide a silver halide photographic material having a hydrophobic support provided with a back coat layer, which has excellent tape adhesion, and has a type impression made on the back coat layer clearly present even after development processing. It is to be. The second object of the present invention is to have good tape adhesion and
Therefore, it is an object of the present invention to provide a silver halide roll photographic paper having a hydrophobic support provided with a back coat layer and having excellent suitability for continuous development in a roll photographic paper processor. A third object of the present invention is to provide a silver halide photographic material provided with a back coat layer, which has excellent water resistance, especially resistance to developing solutions of the silver halide photographic material, and is therefore suitable for use in processing baths. An object of the present invention is to provide an excellent silver halide photographic material free from detachment of back coat components. Other objects, features, advantages, etc. of the present invention will be understood from the following description. As a result of intensive studies by the present inventors, the object of the present invention is to have a silver halide photographic constituent layer on one side of a hydrophobic support, and a synthetic binder, an inorganic antistatic agent, and a molecular layer on the opposite side. A compound having two or more epoxy groups or ethyleneimino groups in it,
Contains polyvalent metal salts or complexes, and the coating liquid is 6.0
It has been found that this can be achieved by providing a back coat layer that is coated while maintaining the above-mentioned temperature, and this has led to the present invention. The silver halide photographic material according to the present invention does not produce unpleasant partial fog called static marks. Also, development, fixing (or bleach-fixing)
Even if you stack them after washing and drying them, they will not stick to each other due to static electricity and become difficult to handle. The silver halide photographic materials of the present invention do not contaminate processing baths, printers, etc. with backcoat coating compositions. In the silver halide photographic material according to the present invention, the type imprint on the back side does not disappear or become thinner during processing so that it no longer plays its role, and even after processing, the type is clearly visible. An impression is obtained. The silver halide photographic material according to the present invention exhibits good tape adhesion, so that the adhesive surface between the adhesive tape for the leader joint and the back coat surface may break during processing in a roll photographic paper processor, resulting in subsequent adhesive failure. Processing of roll photographic paper is not impossible. On the other hand, if one of the constituent elements or conditions of the present invention is missing, each exhibits its own drawback. If a synthetic binder or a compound containing two or more epoxy or ethyleneimino groups in the molecule is missing, sufficient film strength may not be obtained and the type-printed ink may be mixed with part or all of the back coat layer during processing. It disappears. If the inorganic antistatic agent is missing, and the synthetic binder is a conductive binder, the antistatic performance will be insufficient after development, bleach-fixing, and washing, and the stacked prints will stick to each other. It sticks and becomes inconvenient to handle. Polyvalent metal salts or complexes are missing or the pH of the back coat coating is low.
When it is less than 6.0, the tape adhesion is insufficient and the print density after processing is also reduced. The synthetic binder used in the practice of the present invention may be one that can be cured or crosslinked by adhering well to a hydrophobic support with a curing agent having two or more ethyleneimino or epoxy groups in the molecule. Although there are no particular limitations, from the viewpoint of the performance and economical efficiency of the back coat layer, synthetic binders that are advantageously used in the practice of the present invention include those having a carbon number of 4.
Copolymers of the above ethylenically unsaturated copolymerizable monomers and maleic anhydride, hydrolysates or salts thereof, reaction products thereof with polyvinyl alcohol, synthetic polymer latexes, carboxy-modified polyethylenes, etc. I can list combinations of them. Preferred copolymers of ethylenically unsaturated copolymerizable monomers having 4 or more carbon atoms and maleic anhydride, hydrolysates thereof, or salts thereof include α-olefins having 4 or more carbon atoms, alkyl vinyl ethers, and styrene. Examples include a copolymer of an ethylenically unsaturated copolymerizable monomer and maleic anhydride, or a reaction product obtained by hydrolyzing the copolymer with an alkali such as sodium hydroxide or potassium hydroxide. . The molecular weight of the copolymer of an ethylenically unsaturated copolymerizable monomer having 4 or more carbon atoms and maleic anhydride is 2000.
~150000 is preferred. Specific examples include, for example, the pH of a solution obtained by hydrolyzing isobutylene, 1-pentene, butyl vinyl ether, or a copolymer of styrene and maleic anhydride with an alkali such as sodium hydroxide or potassium hydroxide. Examples include reaction products with a value of 5.0 to 9.5. In addition, reaction products of polyvinyl alcohol and water-soluble polymer compounds or salts thereof obtained by copolymerizing these ethylenically unsaturated copolymerizable monomers having 4 or more carbon atoms with maleic anhydride are also included. Included as preferred synthetic binders of the invention. For example, the reaction product of a water-soluble polymer compound or its salt obtained by copolymerization of isobutylene or styrene with maleic anhydride and polyvinyl alcohol is prepared by using the product with the highest possible purity. The degree of polymerization of polyvinyl alcohol used is 500 to 1000, and the reaction conditions need to be adjusted depending on the blending ratio of both, molecular weight, pH of the liquid, and temperature.
Heating at ~98°C for 4 to 6 hours is suitable. The blending ratio (weight) of the copolymer of an ethylenically unsaturated copolymerizable monomer having 4 or more carbon atoms and maleic anhydride and polyvinyl alcohol is preferably 1:1 or less, and the higher the blending ratio of polyvinyl alcohol, the more the back coat is used. The antistatic properties of the layer deteriorate. Preferred synthetic polymer latexes include aqueous dispersions of water-insoluble polymers with an average particle size of 10 to 200 mμ, such as acrylic latex, vinyl acetate latex, styrene-butadiene latex,
Examples include acrylonitrile-butadiene latex. Acrylic latexes include polyesters that are homopolymers of acrylic esters such as methyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate, and methacrylic esters such as methyl methacrylate and butyl methacrylate, or copolymer emulsions thereof. Copolymer emulsion of acrylic latex and ethylenically unsaturated copolymerizable monomer that can be copolymerized with acrylic acid ester or methacrylic acid ester, such as methyl methacrylate/butadiene latex, methyl methacrylate/styrene/butadiene latex, etc. Indeed, those carboxy-modified latexes,
For example, carboxy-modified polyacrylic latex can be mentioned. Vinyl acetate latexes include polyvinyl acetate latex, vinyl acetate/acrylic acid ester copolymer latex, vinyl acetate/ethylene copolymer latex, and their carboxy-modified latexes; styrene/butadiene latexes include styrene/butadiene copolymer latexes, etc. Examples include polymer latex, styrene/butadiene/acrylic ester and/or methacrylic ester copolymer latex, carboxy-modified styrene/butadiene latex, and the like. In addition to these examples, there may also be mentioned copolymer latexes containing monomer units having sulfonic acid. Preferred examples of carboxy-modified polyethylene include trade names such as Zaixen (manufactured by Seitetsu Kagaku Kogyo Co., Ltd.); In the polyethylene resin, some of the ethylene residues may be replaced with olefin residues having 10 or less carbon atoms. Carboxy-modified polyethylene may be dissolved or dispersed in water in the form of a salt with an alkali metal, alkaline earth metal, ammonia, amine, etc. There is no particular restriction on the content of the synthetic binder used in the implementation of the present invention, but from the viewpoint of the balance of various performances of the back coat layer, the content is between 3 mg/m ² and 150 mg/m 2 .
A range of 7 mg/ ^{m 2 to} 60 mg/m ² is particularly preferred. The inorganic antistatic agent used in the practice of the present invention may be any substantially water-insoluble inorganic substance as long as it has an antistatic effect, but typical examples include colloidal silica and fine powder of montmorillonite group minerals. , dispersion or colloid. Particularly preferred inorganic antistatic agents include colloidal silica such as Snowtex-0, Snowtex-20, Snowtex-S, and Snowtex-ZL (all manufactured by Nissan Chemical Co., Ltd.), Na-
Swellable synthetic fluorinated mica compounds such as TS-S (manufactured by Topy Industries, Ltd.), Laponite S, Laponite B
Swelling synthetic fluorine-montmorillonite compounds such as (synthetic hectorite: manufactured by Rapport Industries Limited), Bengel S, Bengel
FW, Bengel HV, Bengel #15, Bengel #23, Bengel #31 (all of the above are Toyojun Yoko Co., Ltd.)
natural montmorillonite compounds such as Kunigel VA (manufactured by Kunimine Toka Kogyo Co., Ltd.), and combinations thereof. The amount of the inorganic antistatic agent used in carrying out the present invention is not particularly limited, but from the viewpoint of the balance between advantageous antistatic performance and film strength, it is preferably in the range of 5 mg/m ² to 1000 mg/m ² . Furthermore, a range of 15 mg/m ² to 500 mg/m ² is particularly preferred. Specific examples of compounds having two or more ethyleneimino groups or epoxy groups in the molecule used in the practice of the present invention are shown below. Further, it is advantageous to dissolve these compounds in a suitable solvent such as water, methanol, ethanol, N,N-dimethylformamide, acetone, ethyl acetate, etc., and then incorporate them into the back coat layer. Furthermore, the content of these compounds is usefully in the range of 2.0% to 100% by weight, particularly preferably in the range of 7.5% to 30% by weight, based on the synthetic binder described in detail above. . Polyvalent metal salts or complexes used in the practice of the present invention include Cu, Mg, Ca, Ba, Zn, Al, Cr,
Examples include salts or complexes of Zr, Sn, Mn, Fe, etc. Preferred are salts or complexes of Cr and Zr. Examples of polyvalent metal salts or complexes used in the practice of the present invention include salts with organic acids such as acetic acid and citric acid, salts with inorganic acids such as hydrochloric acid, carbonic acid, nitric acid, and sulfuric acid;
Examples include complexes with complexing agents such as ethylenediaminetetraacetic acid and propylenediaminetetraacetic acid.
Particularly preferred are chromium alum, chromium sulfate, zirconyl nitrate, zirconyl sulfate, and zirconyl acetate. In order to incorporate the polyvalent metal salt or complex used in the practice of the present invention into the back coat layer coating solution, an aqueous solution or aqueous dispersion of the polyvalent metal salt or complex is prepared in advance, and the aqueous solution or aqueous dispersion is applied to the back coat layer. It can be added to the layer coating components, or it can be added to the aqueous solution or aqueous dispersion to prepare a coating solution. Also,
Aqueous solutions or dispersions of polyvalent metal salts or complexes are prepared after adjusting their pH to 6.0 to 9.5 with an alkaline aqueous solution such as sodium hydroxide or potassium hydroxide or an acid aqueous solution such as hydrochloric acid, sulfuric acid, or phosphoric acid. It's okay to force me. When colloidal silica is used as an inorganic antistatic agent, it may be added after combining an aqueous solution or dispersion of a polyvalent metal salt or complex with an aqueous dispersion of colloidal silica. The content of the polyvalent metal salt or complex is in the range of 1 x 10 ^-2 mg/m ² to 10 mg/m ² , preferably 6 x 10 ^-2 mg/m 2 calculated based on the weight of the polyvalent metal. The content is preferably in the range of ² to 2 mg/m ² . The back coat layer in the present invention exhibits the effects of the present invention only when the PH of the coating liquid is adjusted to 6.0 or higher. In other words, the pH of the coating liquid for the back coat layer
If the coating is applied with a value of less than 6.0, the effect of improving tape adhesion will be extremely insufficient, and the print density after treatment will also be insufficient. If the PH of the coating liquid for the back coat layer is adjusted to 6.0 or higher and applied,
Good tape adhesion is obtained for the first time, and print density is also improved. If the pH of the coating liquid is adjusted to 7.0 or higher, extremely good tape adhesion and printing properties can be obtained. The upper limit of the pH of the coating solution is not particularly limited, but in consideration of the influence of the back coat layer on the silver halide emulsion layer, a pH of 9.5 or less is desirable. When adjusting the PH of the coating liquid for the back coat layer, if the PH of the coating liquid is low, use an inorganic alkali aqueous solution such as sodium hydroxide or potassium hydroxide.
If it is too high, it is desirable to adjust it with an aqueous solution of an inorganic acid such as hydrochloric acid, sulfuric acid, or phosphoric acid or an aqueous solution of an organic acid such as acetic acid or citric acid. Various types of hydrophobic supports can be used in the practice of the present invention. For example, synthetic papers such as polypropylene and polystyrene, films such as cellulose acetate, cellulose nitrate, polyethylene terephthalate, polyvinyl acetate, polystyrene, polyamide, and polycarbonate, as well as films made of paper as a substrate and polyolefin, polystyrene, polyvinyl chloride, etc. Examples include resin-coated paper coated with a resin capable of forming a film, often a polyolefin resin. In particular, as a support for photographic paper, especially roll photographic paper, which requires good tape adhesion and antistatic properties, polyolefin resin-coated paper is advantageous in that the effects of the present invention are more prominently exhibited. used for. In addition, in the resin layer of these thermoplastic resin films or resin-coated papers, white pigments such as titanium oxide, zinc oxide, talc, calcium carbonate, etc.
Fatty acid amides such as stearic acid amide and arachidic acid amide, dispersants such as fatty acid metal salts such as zinc stearate, magnesium stearate, and calcium palmitate, pigments and dyes such as ultramarine and cobalt violet, antioxidants, and fluorescence. It is preferable to contain a suitable combination of various additives such as brighteners and ultraviolet absorbers. The polyolefin resin-coated paper which is advantageously used in the practice of the present invention is manufactured by extrusion coating a molten polyolefin resin onto a running base paper through a slit die in the form of a film. At that time, it is desirable to activate the base paper surface by corona treatment, flame treatment, etc. prior to melt extrusion coating. The thickness of the coating resin layer is not particularly limited, but it is generally advantageous to have a thickness of about 5μ to 50μ. The side of the polyolefin resin-coated paper on which the silver halide photographic constituent layer is provided has a glossy surface, matte surface, silky surface, etc. depending on the purpose, and the back surface is usually a matte surface. Polyolefin resins for coating polyolefin resin-coated paper that are advantageously used in carrying out the present invention include low-density polyethylene, high-density polyethylene,
Examples include homopolymers of olefins such as polypropylene, polybutene, and polypentene, copolymers of two or more olefins such as ethylene-propylene copolymers, and mixtures thereof. ;hereinafter simply referred to as MI) can be used alone or in combination. As base paper for polyolefin resin coated paper, ordinary natural pulp paper,
Although either synthetic fiber paper or so-called synthetic paper made of synthetic resin film may be used, natural pulp paper whose main component is a wood bulb of softwood pulp, hardwood pulp, or mixed pulp of softwood and hardwood is advantageously used. There are no particular restrictions on the thickness of the base paper, but paper with good surface smoothness is preferred, and its basis weight is preferably 50 g/m ² to 250 g/m ² . Further, the base paper mainly composed of natural pulp can contain various polymer compounds and additives. For example, starch derivatives, polyacrylamides, polyvinyl alcohol derivatives, dry paper strength agents such as gelatin, fatty acid salts, rosin derivatives, sizing agents such as dialkyl ketene dimer emulsions, wetting agents such as melamine resins, urea resins, epoxidized polyamide resins, etc. Paper strength agents, stabilizers, pigments, dyes, fluorescent whitening agents, latexes, inorganic electrolytes, PH adjusters, and the like can be contained in appropriate combinations. The back coat layer according to the present invention can contain various polymer compounds and additives. Water-soluble polymers include starch derivatives such as oxidized starch and phosphated starch, gelatin thickeners such as cellulose sulfate, polyacrylamide, poly-N-vinylpyrrolidone, and sodium alginate; surfactants such as alkylbenzene; Anionic surfactants such as sulfonates and sulfosuccinates, nonionic surfactants such as saponins and alkylene oxide compounds,
Amphoteric surfactants such as amino acids, aminosulfonic acids, amino alcohol esters, etc., JP-A-Sho
Fluorine-based surfactants as exemplified in No. 50-99529, etc.
As a fluorescent whitening agent, Japanese Patent Publication No. 45-24068, Japanese Patent Publication No.
Compounds described or exemplified in No. 54-94318 and the like can be contained. Moreover, various matting agents can be contained. In carrying out the present invention, the apparatus for applying the back coat coating liquid onto the surface of the hydrophobic support opposite to the surface on which the silver halide photographic constituent layers are provided include an air knife coater, a roll coater, a bar coater, a blade coater, and a slide coater. Examples include hopper coaters, gravure coaters, flexogravure coaters, and combinations thereof. Prior to coating, it is desirable to activate the surface of the hydrophobic support by corona treatment, flame treatment, or the like. Further, the coating may be carried out by so-called on-machine coating using an on-machine device on a laminator immediately after coating the base paper with the resin capable of forming a film.
So-called off-machine coating may be performed using a separate coating device. Various drying devices are used to dry the applied coating liquid, including hot air dryers such as straight tunnel dryers, arch dryers, air loop dryers, and sine curve air float dryers, and dryers that use infrared rays, heated dryers, microwaves, etc. can be given. The silver halide photographic emulsion layer according to the present invention includes various types. For example, black and white photographic emulsion layer, color photographic emulsion layer, photographic emulsion layer for printing,
Direct positive photographic emulsion layers, etc., but the present invention is particularly useful in roll photographic paper emulsion layers. In addition, such photographic emulsion layers contain binders such as gelatin and gelatin derivatives, chemical sensitizers such as hypo, noble metal sensitizers such as noble metal salts such as gold salts and platinum salts, hexahalogenoiridium () complexes, and hexahalogenoiridium () complexes. High contrast agents such as halogenorhodium () complexes,
Nucleic acid decomposition product, JP-A No. 147925-1983, JP-A No. 147925-1973
Crystal habit modifiers for silver halide grains such as mercapto heterocyclic compounds described or exemplified in No. 107129; color sensitizers cited or exemplified in JP-A-52-65432 and JP-A-52-88340; additives for direct positive photographic emulsions such as fogging agents, dyes for direct positive photographs, dye developers, etc. It is possible to contain additives such as. The silver halide photographic material according to the present invention can be exposed, developed, and processed as described in "Photographic Light-sensitive Materials and Handling Methods" (Kyoritsu Shuppan, written by Goro Miyamoto, Photo Technology Course 2), stop, fix, bleach,
Multi-layer silver halide color photographic materials, which undergo one-bath bleach-fixing treatment after color development, are treated with stabilizers, CD-, CD- (the above two compounds are trade names of Kodatsu Co., Ltd.), droxychrome ( It can be processed with any color developer such as May & Baker Co., Ltd. (trade name). Benzyl alcohol, thallium salt, phenidone, etc. may be added to the developer containing such a main agent. Also,
Useful one-bath bleach-fix solutions are solutions of metal salts of aminopolycarboxylic acids (e.g., ferric complex salts such as ethylenediaminetetraacetic acid, propyleneaminetetraacetic acid, etc.); fixing agents include sodium thiosulfate, ammonium thiosulfate, etc. is useful. Such a one-bath bleach-fix solution may contain various additives. For example, desilvering accelerators (e.g., mercaptocarboxylic acids described in U.S. Pat. No. 3,512,979,
mercaptoheterocyclic compounds described in Belgian Patent No. 682426), antifouling agents, PH regulators or
Various compounds such as a PH buffer, a hardening agent (for example, magnesium sulfate, aluminum sulfate, potassium alum, etc.), and a surfactant can be contained in combination. Also, although such one-bath bleach-fix solutions can be used at various PHs, the useful PH range is PH
It is between 6.0 and 8.0. Next, in order to explain the present invention more specifically,
An example will be described. Example 1 Paper with a basis weight of 160 g/m ² was run at a speed of 80 m/min, and after corona discharge treatment on the back side in the first zone, low density polyethylene (density 0.918, M1 =
5) 50 parts, high density polyethylene (density 0.965, M1
=7) A resin composition consisting of 50 parts is melt-extruded and coated to a resin thickness of 30 μm to form a resin layer with a matte surface.
After corona discharge treatment on the cover surface in the second zone, low density polyethylene (density 0.918,
A resin composition consisting of 30 parts of a masterbatch made by kneading 30% by weight of titanium oxide into MI=8.5), 45 parts of low density polyethylene (density 0.918, MI=5.0), and 25 parts of high density polyethylene (density 0.965, MI=7.0). A resin layer with a glossy surface is formed by melt extrusion coating the object with a resin thickness of 30 μm. In the third zone, after corona discharge treatment is applied to the back resin surface, a rotating 140-mesh gravure roll is immersed in the coating liquid listed in Table 1, the excess coating liquid is scraped off with a blade, and the coating liquid is kept constant. A photographic support with antistatic properties was produced by transferring the mixture onto a surface and drying it. The coating amount of the aqueous coating liquid was 3 g/m ² (moisture).

[Table] Note (1) The blended amount is expressed as a weight composition.
In preparing the coating solution, the 2% chromium alum aqueous solution and the 1N caustic soda aqueous solution were mixed in advance and then added. Furthermore, the pH of the coating solution was readjusted to 8.1±0.2 with a 1N aqueous solution of caustic soda or hydrochloric acid before combining the total amount with water. Furthermore, as the binders and organic and inorganic antistatic agents listed in Table 1, those listed in Table 2 were used.

【table】

【table】

[Evaluation of antistatic performance of back coat layer]

The surface resistivity of the sample was measured at 20° C. and 35% RH for the sample before color development and the sample after color development using a roll processor using the following processing method. Color development (30℃, 3 minutes 30 seconds) → Bleach fixing (30
℃, 1 minute 30 seconds) → Washing with water (30℃, 3 minutes) → Drying (45
℃, 1 minute) [Evaluation of film strength of back coat layer] After immersing in color developer for 3 minutes at 20℃, the sphere diameter was 1 mm.
The ball point needle is set perpendicular to the film surface of the back coat layer, and the load of the ball point needle that causes damage to the back coat film (hereinafter referred to as film strength) is calculated when the sample surface is moved in parallel at a speed of 2 cm/sec. Measure. [Evaluation of type printability of back coat layer] Using an impact printer installed in an automatic printer, a type ribbon (for Kodatsu Back Printer manufactured by Eastman Kodatsu Co., Ltd.) was interposed between the back coat layer surface of the paper stock and the type. Then, information consisting of numbers, letters, lines, etc. was printed in type on the back coat layer surface. After type printing 1
At the 1st, 50th, and 3rd hour, samples with type imprints are processed with a roll processor, and the state of disappearance of the type imprints is observed and judged. [Evaluation of the tape adhesion of the back coat layer] This is a type in which the adhesive layer of the double-sided adhesive tape is present between the end of the leader film and the beginning of the back coat side of the sample cut into a roll with a width of 82 mm. Adhesive with double-sided adhesive tape (Nitto Tape No. 500 (manufactured by Nitto Electric Industry Co., Ltd.) with a length of 15 cm and a width of 75 mm.
The sample is developed using a roll photographic paper processor, and the state of peeling of the adhesive tape is observed and judged. The results obtained are shown in Table 3.

[Table] As shown in Table 3, the sample does not contain a synthetic binder (No. 1) and does not contain a water-soluble epoxy compound, which is a type of compound having two or more epoxy groups or ethyleneimino groups in the molecule. Sample (No. 2) had insufficient film strength and type printability. In addition, sample No. 2 also had poor tape adhesion. Sample containing no inorganic antistatic agent (No. 3,
4, 8, and 9) have poor antistatic performance after development and poor tape adhesion. Samples (Nos. 5 to 7) to which chromium alum, which is a salt of a polyvalent metal, was not added had no problems in antistatic performance, film strength, and type printability, but had insufficient tape adhesion. On the other hand, the samples according to the present invention (Nos. 10 to 12) fully satisfied all performances. As described above, according to the present invention, antistatic performance, film strength, type printability, and tape adhesion can be achieved in a well-balanced manner, but if one of the constituent elements of the present invention is lacking (for PH, see Example 2). ), the performance of one or more of them will be insufficient. Example 2 The same procedure as in Example 1 was carried out except that a coating liquid having a different final pH of formulation No. 10 of Example 1 was used.
Table 4 shows the pH of the coating liquid and the results obtained.

[Table] As shown in Table 4, the back coat layer contains a synthetic binder, an inorganic antistatic agent, a compound having two or more epoxy groups or ethyleneimino groups in the molecule, and a polyvalent metal salt or complex. Samples (Nos. 13 and 14) whose coating liquid pH was less than 6.0 had poor tape adhesion and film strength was rather weak. On the other hand, samples (Nos. 15 to 19) in which the pH of the coating liquid was 6.0 or higher according to the present invention.
It can be seen that it is a well-balanced back coat that has excellent antistatic performance, film strength, type imprintability, and tape adhesion. In addition, from the viewpoint of tape adhesion, the pH of the back coat coating liquid is 7 to 7.
It can be seen that a range of 10 is particularly preferred. Example 3 The amount of chromium alum of formulation No. 10 of Example 1 and the corresponding amount of 1N caustic soda aqueous solution were changed,
The same procedure as in Example 1 was carried out except that a coating liquid with a final pH of 8.1±0.2 was used. The amount of chrome alum used and the results obtained are
Shown in the table.

[Table] As shown in Table 5, tape adhesion improves as the content of polyvalent metal salt increases. If the content is 2 mg/m ² or more, flocs tend to form in the coating solution. Example 4 In place of NER-010 in the formulation No. 10 of Example 1, among the ethyleneimino compounds described in the text, compounds of structural formulas (1) and (3), sorbitol polyglycidyl ether (trade name: Demecol) were used. EX-614 (manufactured by Nagase Sangyo Co., Ltd.) was used in exactly the same manner as in Example 1, except that the same results were obtained. Example 5 Example 3 except that zirconyl acetate, zirconyl sulfate, or magnesium chloride was used instead of chromium alum as the polyvalent metal salt in Example 3.
The same result was obtained in exactly the same manner.

Claims (1)

[Scope of Claims] 1. A silver halide photographic material having at least one silver halide photographic light-sensitive layer on one side of a hydrophobic support and a back coat layer on the opposite side. The back coat layer contains at least a synthetic binder, an inorganic antistatic agent, a compound having two or more epoxy groups or ethyleneimino groups in the molecule, a polyvalent metal salt or complex, and the pH of the back coat coating liquid is 6.0 or more. A silver halide photographic material characterized in that: 2. The silver halide photographic material according to claim 1, wherein the polyvalent metal is Cr or Zr. 3. The silver halide photographic material according to claim 1 or 2, wherein the pH of the coating liquid is 7.0 or higher.